Most database systems use locking for concurrency control. Responsiveness is degraded when transactions spend much time waiting for locks. In those situations in which the lockable units need not be processed in a particular order, differences in the order of processing can make large differences in the durations of the transactions, i.e., responsiveness. Order of processing may be modified by the use of a combination of non-blocking and potentially-blocking lock requests. A simulation is used to investigate the performance of several such algorithms in a variety of settings. Originator-supplied keywords include: Database Management System, Modularization, Pascal, and Tactical Air Control System.